RESUMEN
The misuse of toxic drugsisseriousone of the threats of public health. In this study, toxic Hyoscyami Semen and its adulterants were identified by DNA barcoding. The genomic DNA was extracted from 61 samples including Hyoscyami Semen and its adulterants by reagent kit method. Their ITS2 sequences were amplified, and purified PCR products were sequenced. Sequence assembly and consensus sequence generation were performed using CodonCode Aligner v 4.25. The genetic distances, variable sites and the neighbor-joning (NJ) phylogenetic tree were computed by MEGA 6.0 in accordance with the Kimura 2-parameter(K2P) model. The results showed that the intra-specific genetic distances of Hyoscyamusniger were 0.005 which were smaller than inter -specific ones (0.360) of H. niger and their adulterants. The NJ tree showed that H. niger was clustered into one monophyletic branch, and clearly separated with other species. Therefore, ITS2 sequence was able to identify Hyoscyami Semen and its adulterants to ensure the safty of medicines.